As the diver crouches down to the board, it displaces a certain amount, which is relative to the diver as mass. The diver uses this potential energy to launch themselves into the air, at which point the energy becomes kinetic, at least until the diver reaches the apex of the jump. At this point, the energy will become potential, until the diver begins to fall toward the pool, at which point he or she will accrue kinetic energy until contact with the water.